The present invention relates to a system having one or more processors, such as for the transcoding of digital video signals.
Commonly, it is necessary to adjust a bit rate of digital video programs that are provided, e.g., to subscriber terminals in a cable television network or the like. For example, a first group of signals may be received at a headend via a satellite transmission. The headend operator may desire to forward selected programs to the subscribers while adding programs (e.g., commercials or other content) from a local source, such as storage media or a local live feed. Additionally, it is often necessary to provide the programs within an overall available channel bandwidth.
Accordingly, the statistical remultiplexer (stat remux), or transcoder, which handles pre-compressed video bit streams by re-compressing them at a specified bit rate, has been developed. Similarly, the stat mux handles uncompressed video data by compressing it at a desired bit rate.
In such systems, a number of channels of data are processed by a number of processors arranged in parallel. Each processor typically can accommodate multiple channels of data. Although, in some cases, such as for HDTV, which require many computations, portions of data from a single channel are allocated among multiple processors.
However, there is a need for a single or multi-processor system that selects a processing mode for each video frame to minimize transcoding artifacts, which can appear as visible noise in the transcoded image data. The system should also ensure that the total processing cycles that are required to process frames in buffers of the individual processor or processors do not exceed the available processing power of the transcoders.
The present invention provides a processor system having the above and other advantages.